Bipod and face shield for a rifle



Dec. 25, 1956 c w. MUSSER ETAL BIPOD. AND FACE SHIELD FOR A RIFLE 3 Sheets-Shea 35 as 23 3e 40 a7 Filed NOV. 21, 1952 as 26 27 29 26 a9 INVENTORS FIG. 5 O-WALTON MUSSER FRANCIS w. DIETSCH ATTORNEYS Dec. 25, 1956 c w. MUSSER EIAL 2,775,052

BIPOD AND FACE SHIELD FOR A RIFLE Filed Nov. 21, 1952 3 Sheets-Shea; 5

a1 U 91 J a, 511 EL i-i 1o INVENTORS 49 c WALTON MUSSER FRANCIS v1 mason WV ATTORNEYS:

BIPOD AND FACE SHIELD son A RIFLE C Walton Musser and Francis W. Dietseh, Philadelphia,

Pa., assignors to the United States of America as represented by the Secretary of the Army The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

The present invention relates to a support and face protector useful particularly with rifles of the recoilless type, rocket launchers, or the like, and more particularly to an improved bipod and face shield for such weapons.

Portable firearms of the kind set forth above are designed for firing either from the shoulder or from an emplacement. In the latter case, a combination of supports is usually provided for the firearm comprising a unipod and a bipod which used together form a tripod. in the event of off-shoulder firing, the unipod is disposed in a manner to provide a convenient hand grip or support while the bipod is arranged for movement to an out-of-the-way position in which position it provides a convenient shoulder rest or support.

While firing a weapon of this kind the barrel has a tendency to heat to an extent such that an operator using the sights to adjust for aim is in danger of burning his face upon contact with the barrel. Another problem related to sighting the rifle is that of correction for cant of the rifle. This latter problem is occasioned by an emplacement which is not level or by the slope of a users shoulder. In such cases, unless correction for cant is made, accuracy of the projectile will be impaired.

Although the aforementioned problems are well known to persons skilled in the art, arrangements heretofore proposed, although satisfactory in many respects, are subject to certain inherent limitations. For example, a typical bipod for a rifle is that kind particularly shown and described in U. S. Patent to J. R. Bird, 2,472,804, issued June 14, 1949. This type of bipod is not only useful to provide support for the rifle but it is also useful in correcting for cant. Correction for cant is etfected by an arrangement in which the bracket for supporting the bipod legs pivots independently with respect to the legs. Not only is this arrangement relatively complicated and difficult to manipulate but it tends to be instable since the center of gravity of the rifle is closely adjacent to and above the pivot point. Thus, the rifle is susceptible to falling or pivoting sideways should it not be securely fastened in place. Moreover, the arrangement provides a very limited adjustment for cant and is unsatisfactory in correcting extreme conditions.

It is, therefore, a primary object of the present invention to provide a combination face shield and bipod for a firearm which will overcome the above as well as other disadvantages of prior art arrangements.

Another object of the present invention is to provide an improved bipod for a rifle which is adjustable to effect correction for cant of the rifle, and a face shield which cooperates with the bipod to secure the rifle in a cant corrected position.

It is also an object of the present invention to provide an improved bipod which is semiautomatic in adjustment of the bipod legs.

Still another object of the present invention is to provide ice a combination face shield and bipod for a rifle which is relatively simple in construction, efficient in operation and which is also relatively inexpensive to manufacture.

It is a further object of the present invention to provide an improved cant correcting arrangement for rifles which is conveniently adjustable by the operator when firing from either a prone position or from an ofl shoulder position.

Still further, it is an object of the present invention to 0 provide an improved cant correcting arrangement for rifles which provides a maximum range of adjustment.

A still further object of the present invention is to provide a cant correcting arrangement which is quickly and easily adjustable.

Additionally it is an object of the present invention to provide an improved face shield for a rifle which is highly eflicient in protecting the user of the n'fle against burns.

In accordance with the present invention, the face shield comprises a sleeve encompassing a rearward portion ofa rifle barrel. The bipod which is attached to a second sleeve disposed about the barrel, is arranged for rotation with respect to the barrel thereby to provide cant correction for the rifle. The face shield and bipod sleeve are arranged in a manner to cooperate in locking the bipod in a cant corrected position and in locking the bipod legs in an adjusted position. In addition, the bipod legs are arranged to be movable simultaneously with respect to each other in response to movement of either leg member alone. The legs are also arranged for movement between a position close to and parallel to the rifle barrel and a position normal thereto.

The novel features of the present invention, as well as additional objects and advantages thereof, will be understood better from the following detailed description of a preferred embodiment of the invention when read in connection with the accompanying drawings in which:

Fig. l is a side elevation of a recoilless rifle provided with a face shield and bipod in accordance with the present invention, a forward portion of the rifle barrel being broken away and the bipod being shown disposed in a position for firing from an off-shoulder position;

Fig. 2 is a sectional view tfien on the line 2-2 of Fig. l, to show in broken line outline, an adjusted position of the rifle with respect to the bipod to effect cant correction;

Pig. 3 is an enlarged sectional view of a portion of the apparatus taken along the line 33 of Fig. 1;

Fig. 4 is an enlarged sectional view of another portion of the apparatus taken along the line 4-4 of Fig. 1;

Fig. 5 is a view similar to Fig. 4, but taken along the line 5--5 of Fig. 1 and showing particularly the arrangement for effecting locking of the parts in an adjusted cant corrected position;

Fig. 6 is a side view of a portion of the apparatus, illustrating the bipod disposed in a position for supporting the rifle for firing from a prone position;

Fig. 7 is a sectional view of the apparatus, taken along the line 7-7 of Fig. 6, and showing the bipod legs in juxtaposition prior to spreading thereof;

Fig. 7A is a view similar to Fig. 7, but showing the bipod legs spread apart and arranged for cooperation with the unipod to provide a tripod support for the rifle;

Fig. 8 is an enlarged sectional view showing details of the pivotal connection of the bipod legs to the bracket used to attach the bipod to the rifie, the view being taken along the line 8-8 of Fig. 6 and showing the legs in juxtaposition;

Fig. 8A is a view similar to Fig. 8, but showing the legs spread apart;

Fig. 9 is a front, sectional view of a portion of the apparatus shown in Fig. 6, taken along the line 9-9 of Fig. 6, with portions thereof broken away to show construction details and with bipod legs shown in juxtaposition;

Fig. 9A is a view similar to Fig. 9 but showing the bipod legs spread apart;

Fig. 10 is a sectional view of the apparatus taken along the line 1010 of Fig. 9;

Fig. 11 is a view similar to Fig. 10 but taken along the line 1111 of Fig. 9; and

Fig. 12 is a bottom view of a portion of the apparatus, taken along the line 12-12 of Fig. 1. I

Referring more particularly to the drawings, wherein similar reference characters are used to designate corresponding parts throughout, the present invention is shown applied to a recoilless rifle 1 of conventional design such as that shown, described and claimed in the copending application of G. S. Bluford et al., Serial No. 209,892, filed February 7, 1951. In general, the recoilless rifle 1 comprises the following: a barrel 3, the rear portion of which tapers outwardly and rearwardly to provide a chamber 5; a breech venturi ring 7, which is secured to the rear of the chamber; a breech block 9 secured to and partially closing the rear of the breech venturi ring; a trigger housing and hand grip 11 secured to the barrel; and a sight 13 of the direct telescopic type for aiming the gun in conventional manner.

The recoilless rifle 1 herein described is adapted for firing from either an ofl-shoulder position or a prone position. In the off-shoulder position, the hand grip 11 assists in supporting the front portion of the rifle while, at the same time, the rear portion is placed upon the shoulder of the user for support. Also attached to the barrel 3 is a unipod 15 which further assists in supporting the rifle in the off-shoulder position. Any suitable type of unipod may be employed; such, for example, as the unipod particularly shown and described in the copending application of C Walton Musser et a1., Serial No. 321,962, filed concurrently herewith. In addition thereto, the unipod is also used in firing from a prone position. In the prone position, the unipod 15 functions to support the forward portion of the rifle and the bipod 17, which is also attached to the barrel but rearwardly of the unipod, functions to support the rearward portion of the rifle. In other words, the unipod 15 and bipod 17 combine to form a tripod for the rifle 1.

The telescope sight 13 may be mounted on the rifle barrel 3 in any suitable manner and in a location to make sighting of the rifle convenient. Generally speaking, this location is such that a user of the rifle is able to control firing in the oflF-shoulder position by grasping the trigger housing and hand grip 11 with his right hand and grasping the unipod 15 with his left hand while he himself is located on the left side of the weapon. In such a position, with his head in front of the rifle chamber 5, the right side of his face can be placed against or close to the rifle barrel 3 and in a position to enable him to look through the sight 13 thereby to train the rifle on its target.

The face shield From the standpoint of safety, that is, in order to protect the users face against burns from the rifle barrel 3 which becomes quite hot during continuous firing, the present invention contemplates the use of a face shield 19. As best shown in Fig. l of the drawings, the face shield 19 comprises a cylindrical sleeve disposed to encompass a rearward portion of the rifle barrel 3 and in back of the telescope sight 13 in a position convenient for the user to rest his face against it. The face shield may be made from any suitable heat insulating material, preferably bonded glass fiber material, certain types of plastic, or the like. It may also be made from any material (even metal) of radiation calorimeter type which is coated on the interior with a polished heat reflecting surface.

The face shield 19 is of a diameter greater than the external diameter of the rifle barrel so that it can be sup- 4 ported in spaced relation to the barrel thereby to provide a heat insulating air space therebetween.

In order to support the face shield 19 in spaced relation to the rifle barrel 3, collar members 21, 23 are provided and disposed one at each end of the shield. The collar member 21 disposed forwardly on the barrel, that is, remote from the rifle chamber 5, comprises a two-piece arrangement. The first one 25 of the two pieces is an annular member which is attached to the external surface of the rifle barrel in any convenient manner suitable to secure it against movement with respect to the barrel. The rearward portion 26 of this first piece is offset to an extent such that the inside and outside diameters thereof are substantially equal to the diameters of the face shield 19. The external surface of this rearward portion is threaded. The second one 27 of the two pieces comprises an annular member having an internal diameter substantially equal to the external diameters of the shield 19 and the first piece 25. An annular flange 28 is provided on the internal surface intermediate the ends of this second piece. 31 of the second piece 27 is threaded complementary to the threaded exterior of the first piece 25 so that the two pieces can be threadedly engaged.

The collar member 23 disposed nearest the chamber 5, that is, rearwardly on the barrel, is somewhat longer than the first described collar member 21. This rearwardly disposed collar member comprises an integral piece having a cylindrical portion 33 and a rearwardly extending, outwardly tapered, annular portion 35. An annular flange 36 is provided on the internal surface of the cylindrical portion adjacent to the end 37 thereof located remote from the tapered portion 35. The rearwardly extending portion 35 is tapered substantially equal to the taper of the barrel rear portion providing the chamber 5 so that it can be brought into surface contact therewith. This collar member 23 is disposed about the rifle barrel and arranged so that it is freely movable with respect thereto. In other words, it is movable longitudinally of and rotatably about the barrel.

The face shield 19 is mounted for support between the two collar members 21, 23 with the forward end 38 of the shield disposed within the rearwardly extending portion 39 of the forward collar member 21 and with the rearward end 40 of the shield disposed within the cylindrical portion 33 of the rearward collar at the end 37 thereof remote from the tapered portion 35. With this arrangement, as the second portion 27 of the forwardly disposed collar member 21 is turned or screwed in a direction rearwardly of the rifle, the flange 28 carried by this portion will abut with the forwardly disposed end 38 of the shield and urge the shield rearwardly. Continned movement rearwardly will engage the rearwardly disposed end 40 of the shield with the flange 36 of the rearward collar member 23. In turn, the rearward collarwill cause the tapered portion 35 thereof to move rearwardly along the chamber 5 exterior surface to etfect a locking action for the bipod in a manner to be explained hereafter.

Further, in order to accommodate, without interference to the operation thereof, the mechanical linkage 41 which connects the trigger 43 and the firing mechanism (not shown) contained in the breech block 9, the face shield 19 is spaced from the barrel a distance suflicient to allow the linkage to extend through the space between the shield and the barrel. Thus, the face shield also functions to protect the linkage over a substantial portion of its length. Since the linkage must emerge from behind the shield at the rearward end 40 thereof, the collar 23 at that end is provided with an aperture 45 in the cylindrical portion 33 through which the linkage can be extended without interference.

The bipod The bipod 17 for supporting the rearward portion of the rifle comprises a pair of leg members 47, 49 and a bracket A portion 29 of the internal surface of one end 51 for attaching the legs to the rifle. The bracket i includes a main body portion, sleeve or ring 53 comprising the frustum of a cone the side wall of which is tapered substantially equal to the taper of the barrels rear portion providing the chamber 5. The smaller diameter of the body portion 53 is substantially equal to the diameter of the rearwardly disposed end 39 of the rearward collar 23 tapered portion 35. Thus, when the body portion 53 is disposed about the chamber 5 and in abutment with the end 39 of the collar tapered portion, it will combine therewith to form substantially a continuous tapered surface. Like the rearward collar 23, the bracket 51 is mounted on the barrel so that it is freely rotatable about the axis of the barrel and freely movable longitudinally thereof. This arrangement permits the bipod legs to be adjusted to depend from the rifle, thereby making it possible to correct for cant of the rifle. The main body portion 53 of the bipod bracket is provided with a hollow boss or extension 55 on its outer surface to provide a convenient arrangement for pivotally connecting the leg members to the rifle.

The leg members 47, 49 are of a length suitable to provide a support for the rifle for convenience in firing from either prone or off-shoulder positions. Although no particular design or shape of the leg member is required, it has been found advantageous to have the leading or forward faces 57 of the leg members substantially straight or even so that they will lie parallel to and flat against the face shield. The opposite sides 59 of the leg members are cut away to provide an arcuate shaped portion 61 remote from the free end 63 for convenience and comfort in accommodating the shoulder of a user of the rifle, thereby to lend support to the rifle during firing in the off-shoulder position. Aside from that, the free ends 63 are designed to provide a suitable base for each leg member when the bipod is adjusted for firing from a prone position.

In order to adjust the legs to a proper position for firing the rifle, it is essential to provide a connection which will enable them to be moved in a first plane between a position parallel to and alongside the face shield 19 and a position normal thereto, that is, extending outwardly from the rifle. On the other hand, it is also required that the leg members be adjustable with respect to each other in the depending position and in a plane normal to the first mentioned plane, that is, they should be adjustable from juxtaposition to a spread-apart or angularly related position. Adjustment of the legs in the manner aforesaid is accomplished by a pivotal arrangement or connec 'on provided between the legs and the bracket 51. The arrangement comprises a ball and socket joint in which the socket element is provided by the boss 55 and the ball or pivot element is carried by a separate insert or connector 65 aflixed to each leg.

As shown particularly in Figs. 8 and 8A of the drawings, each insert or connector 65 comprises a spherical element or portion 67 and a guide member 69 extending radially from the spherical portion. Both spherical portions are of diameters suflicient to permit placement thereof within the hollow interior of the boss 55 so that they are in contact with portions of the bosss walls 71 as well as in contact with each other at adjacent points on their surfaces. In this regard, the boss is hollowed out to an extent and shape to provide a bearing surface for the spherical portions. Hence, the width dimension of the boss interior is equal to the diameter of each spherical portion and the length is equal to the combined diameters of the two portions. The depth of the boss (that is, the distance between the open top, which is disposed adjacent to the rifle chamber 5, and the interior surface of the bottom wall 89) is slightly smaller than the diameter of each spherical portion so as to effect a locking action for the bipod legs. In other Words, the inside diameter of the bipod sleeve 53 is reduced by the portion of the spherical members extending beyond the inside Wall of pivotal the boss. Thus, the face shield rearward sleeve 23, u on being moved rearwardly, cannot move the bipod sleeve sufli'ciently for it to become wedged against or locked with the chamber, but will force the bipod sleeve and the spherical members to become locked with the chamber. Thus, in the assembled position, the spherical portions are located within the interior of the boss 55 between the walls 71 thereof and the external surface of the chamber 5.

The guide member 69 of each connector comprises a main body portion 73 in the form of a rectangular prism having two parallel, spaced apart extensions, ribs or ears 75 projecting laterally therefrom. A cylindrical portion 77 extends from one end of the body portion and is adapted and arranged to fit with-in a recess 79 provided in the ends of each leg member. A boss 81 is provided on the opposite end of the body portion which is adapted and arranged to fit within a recess 83 provided in the spherical portion 67 in a manner to facilitate attaching the two together securely. Any suitable means, such as brazing, or the like, may be employed for attaching the spherical portion 67 to the guide member 69 or for attaching the guide member to each member. However, for convenience in assembly and disassembly of the bipod, the guide members 69 herein disclosed are attached to the leg membe'rs by inserting a spring pin 85 respectively through each leg and guide member.

Each of the spherical portions 67 has a segment cut away therefrom of a size sufficient to receive a portion of the main body 73 of the guide member 69 and allow portions of the free ends of the extensions to protrude beyond the spherical surface. In this manner, the fingers or extensions 75 of each guide member can be interengaged with the fingers of the other guide member and yet allow the spherical surfaces to come in contact at adjacent points.

In order to accommodate the guide members and allow for movement of the legs between the positions outlined above, it is necessary to provide openings in the walls of the boss 55. These openings are provided in the front or forwardly disposed wall 87 and in the bottom wall 89 of the'boss. Both openings extend through the wall thicknesses so that the guide members 69 of each connector 65 can extend therethrough and connect the legs with the spherical or ball portion 67 of the pivot joint. The opening in the front is of a width substantially equal to the combined widths of both guide members when assembled and with the legs juxtaposed. The size of this opening is such that the Walls 91 defining the opening function not only as guides but also as stops to restrict the leg members against separation.

The opening in the bottom wall is of a width substantially equal to the thickness of each guide member so that the walls defining this opening limit forward or backward movement of the legs once they are separated. The walls 93 defining the ends of this opening are tapered outwardly from the wall defining the boss interior, thereby to permit spread of the legs when disposed downwardly. In addition, the tapered walls function as stops to limit the degree of spread of the legs, as illustrated particularly in Fig. 8A of the drawings.

Assembly of the bipod pivotal arrangement is accomplished prior to mounting the bipod on the rifle. The connectors 65, after first being assembled, are arranged with their guide extensions 75 intermeshed in tongue and groove fashion, as shown in Figs. 9 through 11 of the drawings. In such a position, the extensions of each connector are arranged adjacent to the pivotal axis of the connector and parallel to the plane of movement of the leg members upon being spread apart. The connectors are next placed within the hollow interior of the boss 55 from the open side of the boss which is normally located next to the rifle barrel so that the guides 69 extend through either opening in the front and bottom wall portions. The spherical portions are arranged in contact with the walls of the boss interior, the walls providing bearing surfaces therefor to permit pivotal movement of the guides. The leg members 47, 49 are then attached to the guides using a spring pin 85 to securely fasten them together.

From the foregoing description, it will be recognized that the combination bipod and face shield of the present invention possesses distinct advantages over arrangements heretofore proposed. Not only is the bipod adjustable between a position parallel and next to the rifle barrel 3, as shown in Fig. 1 of the drawings, and a position normal thereto, that is, laterally extended downwardly from the rifle barrel, as shown in Fig. 6 of the drawings, but also the legs are not readily displaceable from either adjusted position. The latter advantage is facilitated by two factors, namely: first, the stops provided by (l) the walls of the boss which prevent forward movement of the legs while they are disposed downwardly and spread apart, and (2) the walls of the boss which prevent the legs from being spread apart while juxtaposed; and second, the legs cannot be moved except simultaneously.

Simultaneous movement of the legs is effected by interengagement of the guide members 69. The ears 75 of the guide members not only function to prevent the leg members from being rotated about their longitudinal axes, but also cause simultaneous movement of both legs when either leg is alone adjusted from one position to another. Thus, if either leg is moved betweena position parallel and next to the rifle and a position laterally extended from the rifle, the guides will cause the other leg to move simultaneously therewith. Likewise, if the leg members are disposed laterally extended from the rifle, movement of either leg outwardly to spread the legs apart will cause the other leg to move outwardly in the opposite direction. This interaction is best shown in Figs. 8 and 8A of the drawings and will be found to operate as follows: the wall portion 95 of the right-hand connector is engageable with the upper protruding surface 97 of the left-hand connector ear in such a manner that, regardless of the direction of spreading movement of either leg, the other leg will be moved in an opposite direction. For example, from the position of the components shown in Fig. 8, it will be observed that, if the right-hand leg member 47 is moved away from or spread apart from the left-hand leg member 4 9, the spherical portion 95 will pivot and move in a counterclockwise direction and influence the connector 65 of the left-hand leg member to pivot and move in a clockwise direction. This interaction, of course, will take place in an opposite sense should either leg member be moved alone to return it to its normal juxtaposition with theother leg member. The interaction of the leg members has particular advantage in that it enables an operator to quickly adjust the legs by a simple operation. Other arrangements heretofore provided have required each leg member to be rifle can be rotated with respect to the bipod to correct for cant. Locking and unlocking of the parts is quickly and easily accomplished by rotating the annular ring 27 of the forwardly disposed collar member in the proper direction, thereby either to bias or to relieve the bias on the bipod sleeve 53.' This can conveniently be accomplished by an operator using his left hand to operate the locking ring 27, while his right hand grasp the trigger housing and hand grip 11 to rotate the rifle and correct for cant. Thus, as illustrated in Fig. 2 of the drawings, with the bipod 17 in a fixed position, the rifle 1, illustrated in broken line outline, requires cantcorrection.

An operator (not shown) simply by unlockin'gthe bipod from engagement with the rifle can grasp the trigger handle 11 and move it in the direction of arrow. A to the cant corrected position shown in solid line outline. Once arranged in the proper position the parts again are locked in place. to operate but possesses the additional advantage that a maximum adjustment for cant correction can be made as well as a more accurate and quicker means of adjustment. Moreover, the cant correcting arrangement is not subject to easy displacement and provides a stable equilibrium for the rifle since the center of gravity of the rifle is located on the center of rotation within the main body portion 53 of the bipod bracket.

In addition to the locking feature provided by the face shield to hold the rifle in a cant corrected position, the arrangement will also lock the bipod legs against movement. Thus, at the same time the bipod bracket 51 is biased into frictional engagement with the rifle chamber 5, the spherical portions 67 of the connectors 65 will be wedged between the walls 71 of the boss and the chamber exterior surface. This is due to the depth of the boss interior being slightly smaller than the diameter of each spherical portion. Wedging of the spherical portions in this manner will, of course, cause them to be frictionally held against rotation and hence lock the bipod legsin whatever position they are adjusted to. As a result, the arrangement enables the rifle to be moved from one place to another without displacement of the supports.

Although there ha been shown and described but one form of the present invention, it will undoubtedly be apparent to those persons skilled in the art that many other forms thereof, as well as variations in the particular one described, are possible within the spirit of the invention. For example, each of the bipod legs may be made with a telescope arrangement to permit extension thereof. Other changes of like character will, no doubt, readily suggest themselves. Therefore, it is desired that the present invention shallnot be limited except insofar as is made necessary by the prior art and by the spirit of the appended claims.

We claim:

1. A support for an object comprising a pair of leg members, means for pivotally attaching said leg members to said object, said attaching means being adjustable rotatively relative to said object for selectively po' sitioning said object in a vertical position and including means to allow movement of said leg members in a first plane between a first position substantially normal to said object and a second position substantially parallel to said object but removed from said first position, said attaching means further being operative to allow movement of said members with respect to each other only in said first position in a second plane normal to said first plane, whereby said leg members may be angularly disposed with respect to each other to provide a bipod for said object, and moving means carried by said'leg members operatively connecting said leg members to effect simultaneous movement .thereof.

2. The invention as defined in claim 1 wherein said leg member moving means comprises a plurality of parallel spaced-apart ribs, said ribs being disposed adjacent to the pivotal axis of said members and parallel to said second plane, respective ribs of said members being interengaged in tongue and groove fashion.

3. The invention as defined in claim 2 wherein each said leg member is provided with means operatively engaged with at least one rib of the other leg member of said pair of'leg members for effecting simultaneous movement of both said members relative to each other in response to movement of either member alone.

The arrangement is not only simple 4. The invention as defined in claim 1 wherein said pivotal attaching means comprises a ball and socket joint, said ball being provided on one end of each said leg member, said socket comprising a housing on said attaching means.

5. The invention as defined in claim 1 and wherein locking means is provided on said object in engagement with said attaching means for locking said object and said support in an adjusted position.

6. In a gun having a barrel, a cant corrective support therefor comprising a first sleeve encompassing a portion of said barrel, a second sleeve encompassing another portion of said bzirrel, said second sleeve being disposed substantially in contact with said other barrel portion and being movable rotatively relative thereto thereby to effect cant correction for said gun, support means for said gun comprising at least two legs carried by said second sleeve, and locking means carried by said gun operatively connected with both said sleeves for effecting locking engagement of said second sleeve in an adjusted position relative to said barrel.

.7. The invention as defined in claim 6 wherein said legs are pivotally connected to said second sleeve, said pivotal connection having means for permitting movement of said legs between a first position substantially parallel to and alongside of said first sleeve and a second position substantially normal to said first position, said last mentioned means being arranged to allow limited angular movement of said legs in said second position disposed in other than said second position.

8. The invention as defined in claim 6 wherein said locking means engages said first sleeve in a manner to support said first sleeve in spaced apart relation to said barrel.

9. The invention as defined in claim 6 wherein said support means and said second sleeve are disposed in frictional engagement with each other and with said other barrel portion and are so related that in response to locking action of said locking means said first sleeve engages said second sleeve in a manner to move said second sleeve thereby to increase the frictional contact between said support means, said second sleeve and said other barrel portion.

References Cited in the file of this patent UNITED STATES PATENTS 621,085 Hookham Mar. 14, 1899 681,439 Carr Aug. 27, 1901 805,189 Dubert Nov. 21, 1905 1,379,339 Haskell May 24, 1921 2,420,267 Sefried May 6, 1947 2,436,349 Adams Feb. 17, 1948 1 2,472,804 Bird June 14, 1949 2,489,283 Garand Nov. 29, 1949 

